cryptix.provider.cipher
public final class DES extends Cipher implements SymmetricCipher
This algorithm has been seriously analysed over the last 30 years, and no significant weaknesses have been reported. Its only known flaw is that the key length of 56 bits makes it relatively easy to brute-force it.
To overcome this near-fatal flaw, it is recommended that DES be used in Triple DES mode. The JCA algorithm name for the recommended form of Triple DES is "DES-EDE3/CBC", which is implemented by the DES_EDE3 and CBC DES was written by IBM and first released in 1976. The algorithm is freely usable for both single and triple encryption.
References:
Copyright © 1997
Systemics Ltd on behalf of the
Cryptix Development Team.
All rights reserved.
$Revision: 1.6 $
Since: Cryptix 2.2.2
Constructor Summary | |
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DES()
Constructs a DES cipher object, in the UNINITIALIZED state.
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Method Summary | |
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Object | clone()
Always throws a CloneNotSupportedException (cloning of ciphers is not
supported for security reasons). |
int[] | crypt3(int E0, int E1)
Implements the Unix crypt(3) algorithm.
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protected void | des(byte[] in, int inOffset, byte[] out, int outOffset, boolean encrypt)
Encrypts/decrypts a block, of length BLOCK_SIZE.
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int | engineBlockSize()
SPI: Returns the length of an input block, in bytes.
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void | engineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the
specified key.
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void | engineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the
specified key.
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protected int | engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset)
SPI: This is the main engine method for updating data.
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protected void | finalize() Cleans up resources used by this instance, if necessary. |
static LinkStatus | getLinkStatus()
Gets an object representing the native linking status of this class. |
static void | main(String[] argv) Entry point for self_test . |
This method is intended only for use by the class cryptix.tools.UnixCrypt, and should not be used directly by applications.
Parameters: E0 first 32 bits of input. E1 second 32 bits of input.
Parameters: in an array containing the input block inOffset the starting offset of the input block out an array containing the output block inOffset the starting offset of the output block encrypt true to encrypt, false to decrypt
Returns: the length in bytes of an input block for this cipher.
Parameters: key the key to use for decryption.
Throws: InvalidKeyException if one of the following occurs:
Parameters: key the key to use for encryption.
Throws: InvalidKeyException if one of the following occurs:
in and out may be the same array, and the input and output regions may overlap.
Parameters: in the input data. inOffset the offset into in specifying where the data starts. inLen the length of the subarray. out the output array. outOffset the offset indicating where to start writing into the out array.
Returns: the number of bytes written.
Throws: CryptixException if the native library is being used, and it reports an error.
self_test
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